1. Field of the Invention
The present invention is in the field of lighting fixtures and pertains more particularly to a lighting fixture specially adapted for the mounting of elongate fluorescent lamps as the illuminating medium.
2. The Prior Art
Lighting fixtures, and particularly fluorescent lighting fixtures, have achieved widespread use. The typical fluorescent lighting fixture comprises a rectangular or round housing intended to be secured to the ceiling and carries the usual electrical contacts which also support the lamps. The housing typically includes side and end walls which together define a downwardly open mouth portion. A diffuser, normally of polymeric material, is mounted to the housing, often by the interengagement of tangs or prongs on the diffuser which fit into apertures complementally spaced on the housing.
In order to open the fixture, as for the replacement of lamps it is merely necessary to flex the resilient diffuser so as to unseat the tangs from the support apertures, whereupon the diffuser may be removed, providing access to the tubes.
In accordance with a further type of fixture, the housing carries a metallic frame within which the diffuser is seated. One edge of the frame is hingedly connected to the housing, and means, such as screws, latches or the like, are supported on an opposite edge of the frame from the pivot edge. Replacement of lamps is effected by releasing the screw or latch arrangement, whereupon the frame and diffuser are free to pivot clear of the housing.
The conventional fixtures described fail to provide a tight seal with the housing, with the result that spaces between the noted parts, in addition to forming undesirable cracks or light passages, also permit the ingress of insects, moisture, detritus and the like into the space between the housing and the diffuser, necessitating frequent cleaning.
Such fixtures are disadvantageous for the further reason that vandals may readily open the same and abstract bulbs, starters and the like.